keep a reference to the datachannel to avoid buggy garbage collection

data_channels.js

 /* global connection, Strophe, updateLargeVideo, focusedVideoSrc*/
+
+// cache datachannels to avoid garbage collection
+// https://code.google.com/p/chromium/issues/detail?id=405545
+var _dataChannels = [];
+
 /**
  * Callback triggered by PeerConnection when new data channel is opened
  * on the bridge.
  * @param event the event info object.
  */
+
 function onDataChannel(event)
 {
     var dataChannel = event.channel;
     dataChannel.onclose = function ()
     {
         console.info("The Data Channel closed", dataChannel);
+        var idx = _dataChannels.indexOf(dataChannel);
+        if (idx > -1) 
+            _dataChannels = _dataChannels.splice(idx, 1);
     };
+    _dataChannels.push(dataChannel);
 }
 
 /**